Suspension mechanism for light fixtures



Oct. 6, 1959 F. E. WEBB SUSPENSION MECHANISM FOR LIGHT FIXTURES Filed Jan. 22, 1957 INVENTOR. Francis E 1'16 Webb BY fla 4.!

United States Patent Ofifice SUSPENSION MECHANISM FOR LIGHT-FIXTURES Francis Erle Webb, Portland, Oreg. i

Application January 22, 1957, Serial No. 635,398

6 Claims. (Cl. 248343) This invention relates to suspension mechanism for light fixtures and more particularly to mechanism for vertically suspending pendent light fixtures which accommodates swinging movement of the light fixtures relative to the structure supporting the fixture.

Generally, it is an object of this invention to provide an improved suspension mechanism for light fixtures employing a vertical support shaft wherein the shaft is free to swing relative to the structure supporting the fixture but is constrained from rotary movement about the axis of the shaft.

Another object of this invention is to provide a suspension mechanism for light fixtures which is sightly in appearance and economically produced and which is particularly adapted for manufacture from pressings and die castings without using machined parts.

Pendent light fixtures such as the usual ceiling fixture having one or more lamps carried at the base of a supporting shaft preferably should be allowed a certain amount of free swinging movement to safeguard the fixture from damage which might otherwise occur in the event an object inadvertently strikes the base of the fixture. It is desirable that the fixture realign itself vertically from the ceiling upon coming to rest without assuming a skewed position. In addition to proper vertical alignment, it is highly advantageous that the fixture be constrained from rotation about the axis of the vertical supporting shaft. Modern lighting fixtures often employ shades or louvers, or other decorative features, which incorporate linear or rectangular lines in their design. For instance, the shade elements for afixture may take the form of concentric rectangular rings. For reasons of appeal, fixtures of this typeusually are installed so that the lines of the fixtures occupy a fixed angularity or parallelism relative to the lines of adjacent fixtures and the architectural lines of the surroundings. Rotation of a fixture after it has been installed creates misalignment of these lines and thus spoils the general effect of the fixture. Rotation of the fixture about its support also creates twisting of the conductors of the fixture which should be avoided.

It is also highly desirable that the universal mechanism employed for controlling the movement of the sup porting shaft of fixtures of this type be as compact as possible so that the mechanism will not contribute materially to the overall length of the shaft. Ordinarily, a cap or cover member is installed with a light fixture over the ceiling mounting for the fixture to cover up the ceiling mounting. The various universal devices known heretofore for controlling the movement of the supporting shaft have generally been so large that they have been installed in a shaft below the cap so as to be visible. The suspension mechanism of this invention contemplates a mechanism controlling movement of the supporting shaft which may be manufactured to occupy a very small amount of space and may be readily included in a fixture so as to be covered by the cap normally covering the ceil ing mounting for the fixture.

A more specific object of this invention, therefore, is to provide a suspension mechanism for light fixtures which includes a universal mechanism controlling movement of the support shaft for the fixture wherein the universal mechanism is characterized by a small and compact construction, enabling the universal mechanism to to be incorporated with the fixture between the cover cap for the fixture and the ceiling from which the fixture is suspended. 1

Another object of the invention is to provide a suspension mechanism for light fixtures having a vertical supporting shaft wherein the shaft is free to swing angularly relative to the ceiling mounting for the fixture and wherein the resistance to swinging movement encountered by the shaft is substantially the same in every direction so that torsional stresses within the shaft are maintained at a minimum level.

novel means for securing the fixture to a ceiling, enabling the fixture to be readily installed so that the decorative lines of the fixture are properly positioned relative to the decorative lines of the surroundings.

These and other objects and advantages are attained by the present invention described hereinbelow in conjunction with the accompanying drawings wherein:

Fig. l is a side view of a light fixture embodying this invention, showing the fixture in the position it normally occupies in hanging from a ceiling;

Fig. 2 is a cross-sectional view, slightly enlarged, along the line 22 in Fig. 1, showing the ceiling mounting for the fixture, the universal mechanism controlling move ment of the support shaft in the fixture, and means con meeting a conventional lamp socket to the fixture;

Fig. 3 is a top view along the line 3-3 in Fig. 2;

Fig. 4 is a cross-sectional view along the line 4-4 in Fig. 2; and

Fig. 5 is a side view of the fixture, partially broken away, showing the position of the parts in the fixture when the support shaft is swung angularly relative toa lamp shield 19. Shade elements 16, 17, and 18, and

shield 19 are supported at the lower end of fixture 10 by means of wire suspension brackets 21. The upper ends of brackets 21 are hooked into a hood member 22 depending downwardly from the lower end of shaft 11 Intermediate crooked portions of bracket 21 provide a support for lamp shield 19, and the lower ends of the brackets are aflixed to the inner shade element 16. Shade elements 17 and 18 are spaced from and supported by the inner shade element by means of brackets 23. The invention is shown in connection with rectangular shade elements or louvers of the type which ordinarily would be installed so that the contours of the elements would occupy a definite angular relationship with respect to the surroundings in a room.

Suspension support 12, at the upper end of support shaft 11, comprises a shaft support member 26 nonrota-tably affixed to the upper end of shaft 11 and a retainer member 27 surrounding shaft support member 26 and pivotally supporting the latter. As can best be seerrin Figs. 2 and 3, retainer member 27 is comprised of tour Patented Oct. 6, 1959.

vertical wall portions 28, 29, 31, and 32 spaced from each other so as to define within the interior of the retainer member a cavity of substantially square cross-section, and a bottom wall 33. Bottom wall 33 of the retainer member extends horizontally inwardly from the base of walls 28, 29, 31, and 32 to join the base of an annular pivot flange 34- inte'grally formed with bottom wall 33. Pivot flange 34 is frusto-conical in shape, having an upper peripheral edge 36 abutting against and providing a support for shaft support member 26.

Shaft support member 26 comprises a central hub section or shaft receiving portion 37 encircling. shaft 11, and a. shoulderportion 38 integrally formed with hub section 37. Shoulder portion 38 surrounds hubsection 37 and extends radially outwardly to opposite sides of shaft 11. Portion 38 has a flat bottom surface. The peripheral edge of shoulder portion 38 has a substantially square outline, save for corner portions thereof which are rounded, enabling support member 26 to be loosely and nonrotatably fitted within the cavity defined by walls 28, 29, 31, 32 of the retainer member. The shaft support member is afiixed to shaft 11 by a cotter pin 39.

When retainer member 27 is secured to a ceiling, pen'pheral edge 36 of pivot flange 34 lies along a horizontal plane. The lower surface of shoulder portion 38 lies along a plane normal to shaft 11. freely hanging from a ceiling, shoulder 38 tends to seat on edge 36 thereby vertically positioning shaft 11.

Annular pivot flange 34,v which is frusto-conical in shape, extends axially upwardly from bottom wall 33, and laterally inwardly from wall portions 28, 29, 31, 32. In this manner, a space is provided between the wall portions and the pivot flange which enables the outer edge of shoulder portion 38 to move freely downwardly below the level of edge 36. Edge 36, which constitutes a pivot edge, abuts the fiat bottom surface of shoulder portion 38. In the embodimentillustrated, the walls of flange 34 slope at about a 45 angle so that shaft 11 is free to swing up to about 45 out of perpendicular while pivoting on edge 36.

Flange 34 is concentric with shaft 11 so that all points about peripheral edge 36 lie equidistant from the center of shaft 11. The retainer member pivots in all directions about pivot points spaced the same distance from thewcenterof shaft 11. In this way, the resistance to swinging movement encountered by the shaft is substantially the same regardless of the direction of pivot.

The peripheral edge of shoulder portion 38 co-operates with the walls of the retainer member, which act as guide portions to hold the shaft support member from rotation within the retainer member. Since the shaft support member pivots on pivot flange 34, no lateral shifting of the shaft support member occurs within the retainer member as would be the case if a ball and socket joint were employed. The pivot connection enables the walls of the retainer member to restrict angular rotation without causing the support member to bind within the confines of the retainer member. It should also be noted that the outer edge of shoulder portion 38 is beveled to insure that the shaft support member moves freely within the retainer member.

Integrally formed at theupper end of retainer member 27 and projecting to either side of the member are a pair of flanges 41 and 42. Each of these flanges contains an arcuate guide slot 43 and 44, respectively, arced about radial centers coinciding with the center of shaft 1 1. These slots provide a means for fastening the retainer .member to the ceiling. When installing a fixture, a

mounting bar '46 is first attached to the ceiling as by screws 45, the bar having a circular cutout 47 which is placed over the point where it is desired to mount the fixture. The retainer member is then loosely affixed to the mounting bar by fastening members such as screws 48'yvhich are inserted through guide slots 43, 44. The retainer member may then be rotated about an.

When the fixture is beneath a pair of spring clamps 53 and 54' carried by coinciding with the center of shaft 11 within the con fines of the guide slots until proper positioning of the shade elements or louver-s of the fixture is attained. Screws 48 may then be tightened to completely secure thefixtureinplace.

As can best be seen in Figs. 3 and 4, at the lower end of the retainer member and projecting outwardly to either side of the member are a pair of lug portions 49 and 51. A cap or cover member 52 is affixed to the retainer member by inserting lug portions 49, 51

cap 52. Cap 52, the retainer member, the shaft support member, and shaft 11 may all be assembled together without the use of a machined part.

Electric conductors 56 and 57 extend downwardly through the shaft support member and through the center of shaft 11 to a conventional lamp socket 58 at the base of shaft 11. Additional conductors connect lamp 14 to conductors 56, 57in a conventional manner.

Socket 58, which is conventional, has a pair of fastening screws 61 and 62 inserted into threaded bores provided at the upper end of the socket. Socket 58 is secured to shaft 11 by a mounting member 66. Mounting member 66 has a hub section and a pair of ear portions 67 and 68. Socket 58 is afiixed to mounting member 66 by inserting screws-61, 62 through accommodating bores provided in ear portions 67, 68. Hub section 65 at the center of the mounting portion encircles the lower end of shaft 11 and is nonrotatably afiixed to the shaft by a cotter pin 69.

Hood member 22 has an end wall 71 containing a circular aperture 72 which is fitted over the upper end of mounting member 66 to seat on a shoulder 73 of hub section 65. The hood member is clamped against shoulder 73 of mounting member 66 by a clamping ring 76. Clampingring 76 is press fitted over the end-of hub sec tion 65 thereby to nonrotatably secure the hood member to the mounting member. By the construction de scribed, the mounting member, hood member, clamping ring, and shaft 11 are all assembled without the use of a machined part.

It will be noted that the above construction has a number of advantages over constructions presently known. Suspension support 12, which includes a universal mechanism nonrotatably suspending shaft 11 but accommodating free swinging movement of the shaft, is

characterized by an extremely compact construction which enables the suspension support to be positioned so as to be covered by the ceiling cap normally employed with light fixtures. The resistance to the swinging movement encountered by shaft 11 is substantially the same in all directions. Torsional stresses within the mechanism are thus eliminated so that the life of the mechanism is considerably prolonged. The upper peripheral edge of pivot flange 34 and the lower surface of shoulder portion 38 insure that the shaft occupies a vertical position when the shaft is at rest and freely hanging from a ceiling. j

Slots 43 and 44 are formed about a common radial center coinciding with the center of shaft 11 enabling the retaining member to be rotated about an' axis coinciding with shaft 11 merely by loosening screws 48 and without entirely removing the retainer member from mounting bar 46. The fixture may be carefully adjusted so that the concentric ring elements carried at the bottom of the fixture are in proper alignment and then finally secured in position. Lug portions 49, 51 together with spring clamps 53 and 54 of the ceiling cap provide a means for clampingthe ceiling cap to the retainer member after the fixture has been properly positioned.

It is claimed and desired to secure by Letters Patent: 1. A suspension mechanism for a lighting fixture comprisinga shaft adapted to carry a lamp at its lower end, a Shaft support member nonrotatably secured to the upper end of said shaft and having a shoulder portion extending radially outwardly from said shaft to opposite sides of said shaft, said shoulder portion having flat bottom surface portions disposed about the perimeter of said shaft, a retainer member adapted to be secured -to a ceiling mounting said shaft support member, said retainer member having an annular pivot flange concentric with said shaft said pivot flange having a peripheral edge disposed beneath said flat bottom surface portions and abutting said bottom surface portions thereby to support said shoulder portion, and a cap member encircling said shaft and covering said retainer and shaft support members When said retainer member is secured to a ceiling, said cap and retainer members having clamp means interposed therebetween whereby said cap member may be releasably clamped to said retainer member. a

2. A device for nonrotatably suspending a shaft comprising, in operative position, a shaft support member; said member having a central shaft-receiving portion adapted to receive and be nonrotatably secured to the end of such a shaft, and a shoulder portion encircling the shaft-receiving portion having substantially flat bottorn surface portions which extend in a horizontal direction on all sides of said shaft-receiving portion; and a retainer member mounting said shaft support member; said retainer member having guide portions engaging said shaft support member to inhibit rotary movement of the support member relative to said retainer member, and an annular pivot flange concentric with said shaftreceiving portion and disposed beneath said bottom surface portions, said pivot flange projecting in an axial direction upwardly toward said bottom surface portions and terminating in a circular pivot edge which abuts said bottom surface portions and supports the shaft support member while accommodating pivotal movement of the same.

3. A device for nonrotatably suspending a shaft comprising, in operative position, a shaft support member; said member having a central shaft-receiving portion adapted to receive and be nonrotatably secured to the end of such a shaft, and a shoulder portion encircling said shaft receiving portion'having a substantially flat bottom surface extending in a horizontal direction on all sides of said shaft-receiving portion; and a retainer member mounting said shaft support member; said retainer member having a base with an aperture therein to accommodate the insertion therethrough of such a shaft, upstanding wall portions integral with said base and arranged on all sides of said shoulder portion, said wall portions snugly encompassing the peripheral edges of said shoulder portion thereby to inhibit rotary movement of said shaft support member relative to said retainer member, and an annular pivot flange concentric with said shaft-receiving portion and disposed beneath said bottom surface, said pivot flange being integral with said base and projecting in an axial direction upwardly toward said bottom surface, said pivot flange terminating in a circular pivot edge which abuts said bottom surface and supports the shaft support member while accommodating pivotal movement of the same.

4. The device of claim 3 wherein the peripheral edges of said shoulder portion have a substantially rectangular outline, and wherein said wall portions of said retainer member define a cavity of substantially rectangular crosssection which nonrotatably receives the shoulder portion of said shaft support member.

5 A suspension mechanism for a lighting fixture comprising, in operative position, a shaft adapted to carry a lamp at its lower end; a shoulder portion at the upper end of said shaft extending radially outwardly from said shaft in all directions around the perimeter of said shaft; said shoulder portion having a substantially flat bottom surface extending in a horizontal direction around said shaft; a retainer member mounting said shaft support member; said retainer memberhaving guide portions engaging said shaft support member for inhibiting rotary movement of the support member relative to said retainer member, and an annular pivot flange concentric with said shaft disposed beneath said bottom surface; said pivot flange projecting in an axial direction upwardly toward said bottom surface and terminating in a circular pivot edge which abuts said bottom surface and supports the shaft'support member while accommodating pivotal movement of the same; and means for securing said retainer member to a ceiling.

6. A suspension mechanism for a lighting fixture comprising, in operative position, a shaft adapted to carry a lamp at its lower end; a shaft support member nonrotatably secured to the upper end of said. shaft; said shaft support member having a shoulder portion extending radially outwardly from said shaft and extending around the perimeter of said shaft; said shoulder portion having a substantially horizontal and flat bottom surface; a retainer member mounting said shaft support member; said retainer member having an annular pivot flange concentric with said shaft, and guide means for inhibiting rotary movement of said support member relative to said retainer member; said pivot flange extending in an axial direction upwardly to a point abutting the bottom surface of said support member and terminating in a circular pivot edge which pivotally supports said shaft support member; and means for securing said retainer member to a ceiling; said means comprising a flange portion carried by said retainer member having an arcuate slot formed therein; said slot adjustably accommodating a fastening member inserted through the slot and aflixed to a ceiling; said slot being arced about a radial center coinciding with the center of said shaft whereby said retainer member may be rotatably positioned about a fixed axis within the confines of said slot when secured to a ceiling by a fastening member.

References Cited in the file of this patent UNITED STATES PATENTS 1,093,332 lockers Apr. 14, 1914 1,824,708 Davis et al Sept. 22, 1921 1,709,444 Thompson Apr. 16, 1929 1,738,652 Hulse Dec. 10, 1929 2,753,445 Thomas et al. July 3, 1956 

